A handgun normally has front and rear sights fastened thereto via its slide. In some instances, the front sight is an integral part of the slide. More commonly, however, the front sight is fastened to the slide by one of a number of methods, such as by mating dovetails, screws or tenons.
Among disadvantages inherent in the fastening of gunsights by screws, are the following:
the screw constitutes a separate component to be manufactured and handled, together with the accompanying expenses;
assembling of a screw-fastened gunsight may be a lengthy and cumbersome operation because of the need to orient the pieces, hold them in a predetermined position for assembly, and then tighten the screw;
screws, when used in environments subject to high mechanical stresses, eventually become loose; and
as both the sight and the gun slide have dimensional tolerances to allow for production and assembly techniques, there exits a certain amount of freedom between the two parts, once assembled. This freedom cannot be eliminated by tightening the screw, and manifests itself as a minor misalignment of the sight relative to the gun.
Among handguns having a front sight fastened by use of tenons is the Colt (.TM.). In particular, the front sight is attached to the slide via a metal tenon (leg) which extends from the base of the sight, and through an opening in the slide. The metal tenon is flattened so as to secure the sight in a fixed position relative to the slide. As the tenon is a solid piece of metal with various inherent internal stresses and a unique, unknown grain structure, the flattening is not fully controllable and is not uniform and may thus result in misalignment of the sight.